06 May Human population bottlenecks?
John Hawks has a nice post concerning evidence for human population size in the stone age. This work relates to Behar et al “The Dawn of Human Matrilineal Diversity” and the press releases and coverage that it has received. Careful reasoning and analysis like he provides though is unlikely to dent more sensational headlines of which there seem to be plenty. All seem to pick out a small size for humans about 70,000 years ago and e.g. “Humanity’s Brush With Extinction“. Hawks however mentions that “The paper itself does not provide any tests of the number of ancient humans indicated by the mtDNA phylogeny.” He then goes on to use the data in that paper to see what can be deduced about population bottlenecks in humans. The post is more like a research article in many ways, carefully outlining the assumptions made. I particularly like his clear treatment up front of “effective population size”, something that I see frequently and incorrectly translated as “probable number of individuals” even by scientists who should know better.
Strangely AminoPop seems confused about what species is under discussion, and their cartoon is labeled with “Homo erectus” instead, which had much more than just a brush with extinction!